1. Technical Field
The present invention relates to a sheet manufacturing apparatus.
2. Related Art
There has been a demand that used paper is processed in office in view of confidentiality because the used paper abandoned in the office may contain confidential material. Wet type sheet manufacturing apparatuses are not suitable to a small scale office because the wet type sheet manufacturing apparatuses use large amount of water. Dry type sheet manufacturing apparatuses which have simple structures have been suggested (for example, please see Japanese Unexamined Laid Open Patent Publication No. 2012-144819).
However, even if the sheet manufacturing apparatuses use same sheet material and perform pressurizing and heating in same way, it is possible that the sheet lacks strength. Inventors of the present invention have found that it is because moisture amount in the stock material has large impact to quality of the sheet being produced.
This is because quantity of heat in heating and pressurizing is used in evaporating the moisture mount in the stock material, when the moisture mount is relatively large. Thus, the quantity of heat to tie fibers is not enough, and the strength of the sheet decreases. On the other hand, the quantity of heat in heating and pressurizing is surplus, when the moisture mount in the stock material is relatively small. Thus, resin to tie the fibers is fused too much and spread, the remaining amount to tie the fibers is not enough. However, there has been no disclosure regarding the impact of the moisture amount to the strength of the sheet.